Fig 3. A. Human MMP-13 mRNA expression in T/C-28a2 chondrocytes transfected with a siRNA against SERPINE2 (siSERPINE2, 10nM) or a non-targeting control siRNA (siC-, 10 nM) in presence or not of IL-1α (0.5 ng/mL) for 24 h. B. MMP-13 endogenous catalytic activity was measured in the conditioned medium of OA human primary chondrocytes after recombinant SERPINE2 (0.4 ng/mL) treatment in presence or not of IL-1α (0.5 ng/mL) for 24 h.

*P<0.05 and ***P<0.001 vs siC- transfected cells; ^### P<0.001 vs siC- plus IL-1α-stimulated chondrocytes.